num = int(input())
if num < 30:
  print("No")
if num >=30:
  print("Yes") num = int(input()) num int(input()) int input() input if num < 30:
  print("No") num < 30 num 30 print("No") print "No" if num >=30:
  print("Yes") num >=30 num 30 print("Yes") print "Yes" num = int(input()) int(input()) num
num = int(input())
if num < 30:
  print("No")
if num >=30:
  print("Yes")